Page 413 - Problem-Based Feline Medicine

20 – THE CAT WITH ENLARGED LYMPH NODES 405

The lymphadenitis is characterized by hemorrhage, abscesses have been reported in plague, with lymph-
necrosis and perinodal edema, and later by lymph node adenopathy due to hyperplasia.
abscessation. Abscesses may rupture and drain thick, ● Pasteurella multocida, a frequent organism found
creamy pus. The severely swollen, inflamed nodes are in bite wounds, resembles Y. pestis cytologically.
referred to as “bubos”. However, bite wounds usually contain a mixed
● This distribution of lymphadenopathy results from bacterial population while bubos usually contain a
oral exposure during hunting. monomorphic population of bacteria.
● Flea bites may occur elsewhere resulting in a dif-
Anthrax.
ferent distribution, e.g. solitary inguinal bubo for-
● Rare.
mation.
● Lymph node abscessation probably does not occur
Other possible signs include oral ulcers, tonsillar as with plague.
enlargement, ocular and nasal discharges and ● Lingual, pharyngeal and cervical edema may be
abdominal distention. Cats may initially present with more pronounced than with plague.
less severe signs.
Tularemia.
Septicemic plague, characterized by fever and septic ● A papule may be present at the site of innoculation.
shock may occur with or without bubo formation. ● Lymphadenopathy is not as prominent, and absces-
sation does not occur.
Pneumonic plague in cats, characterized by fever,
dyspnea, oral or nasal discharges, and coughing or Other causes of bacterial lymphadenitis.
sneezing occurs occasionally and is usually a sequel to ● Unlike most other causes of bacterial lymph-
bubonic or septicemic plague. adenitis, there is usually minimal reaction at the site
of innoculation with plague organisms.
● Culture of organism is required to definitively dif-
Diagnosis ferentiate.

History of exposure to infected rodents. Acute infection with FeLV or FIV and regional lymph-
adenopathy.
Cytology of lymph node biopsy/exudate reveals neutro-
● Retroviral infections have clinically a more sub-
phils and a monomorphic population of Gram-
acute to chronic course.
negative, bipolar staining, coccobacilli.
● Lymph node biopsy with retroviral infections will
FA test of air-dried smears of tissues or exudate. reveal hyperplasia.
Culture of organism from lymph nodes or other
affected tissues (e.g. tonsils). Treatment
Acute (as early as possible once illness is detected) and Treat early on the basis of tentative diagnosis.
convalescent (14 days later) antibody titers demon-
Antibiotics (optimal treatment is not known).
strating a four-fold rise in titer are diagnostic for
● Recommended antibiotics include tetracycline,
plague. Titers are useful to confirm a zoonotic disease
doxycycline, chloramphenicol, trimethoprim-
when treatment is based on a tentative diagnosis.
sulfonamide, streptomycin, gentamicin, and
All plague suspects should have thoracic radiographs kanamycin at standard recommended doses.
taken to rule-out pneumonia. Fluoroquiniolones have been effective experimen-
tally.
● Recommended duration of therapy is 10–21 days.
Differential diagnosis ● Use parenteral treatment initially to minimize
contact of nursing personnel with oral cavity. Use
Cat bite abscess.
follow-up treatment with oral antibiotics to mini-
● Most cat bite wounds result in cellulitis and
mize hospitalization and aminoglycoside toxicoses.
subcutaneous abscessation rather than lymph
node abscessation. However, subcutaneous/muscle Treat animal and environment for fleas.